import { defined } from './defined';
import { DeveloperError } from './DeveloperError';

/**
 * Converts an object representing a set of name/value pairs into a query string,
 * with names and values encoded properly for use in a URL.  Values that are arrays
 * will produce multiple values with the same name.
 * @function objectToQuery
 *
 * @param {Object} obj The object containing data to encode.
 * @returns {String} An encoded query string.
 *
 *
 * @example
 * var str = Cesium.objectToQuery({
 *     key1 : 'some value',
 *     key2 : 'a/b',
 *     key3 : ['x', 'y']
 * });
 *
 * @see queryToObject
 * // str will be:
 * // 'key1=some%20value&key2=a%2Fb&key3=x&key3=y'
 */
function objectToQuery (obj: any): string {
    // >>includeStart('debug', pragmas.debug);
    if (!defined(obj)) {
        throw new DeveloperError('obj is required.');
    }
    // >>includeEnd('debug');

    let result = '';
    for (const propName in obj) {
        // if (obj.hasOwnProperty(propName)) {
        if (Object.prototype.hasOwnProperty.call(obj, propName)) {
            const value = obj[propName];

            const part = encodeURIComponent(propName) + '=';
            if (Array.isArray(value)) {
                for (let i = 0, len = value.length; i < len; ++i) {
                    result += part + encodeURIComponent(value[i]) + '&';
                }
            } else {
                result += part + encodeURIComponent(value) + '&';
            }
        }
    }

    // trim last &
    result = result.slice(0, -1);

    // This function used to replace %20 with + which is more compact and readable.
    // However, some servers didn't properly handle + as a space.
    // https://github.com/CesiumGS/cesium/issues/2192

    return result;
}
export { objectToQuery };
